Means for folding sheets



R. L. SJOSTROM MEANS FOR FOLDING SHEETS Nov. 5, 1968 7 Sheets-Sheet 1 Filed June 25. 1966 INVENTOR. ROBERT L. SJOSTROM Nov. 5, 1968 R. SJOSTROM MEANS FOR FOLDING SHEETS 7 Sheets-Sheet z Filed June 23. 1966 FIG. 4

ts-tfi'r- INVENTOR. ROBERT L. SJOSTROM Nov. 5, 1968 R. SJOSTROM MEANS FOR FOLDING SHEETS 7' Sheets-Sheet 3 Filed June 25. 1966 INVENTOR. ROBERT L. SJOSTROM Nov. 5, 1968 R. SJOST ROM MEANS FOR FOLDING SHEETS 7 Sheets-Sheet 4 Filed June 25, 1966 INVENTOR. ROBERT L. SJOS 7' ROM Nov. 5, 1968 R. 1.. SJOSTROM 3,409,288

MEANS FOR FOLDING SHEETS Filed June 25. 1966 7 Sheets-Sheet 5 Nov. 5, 1968 SJOSTROM I 3,409,288

MEANS FOR FOLDING SHEETS Filed June 25. 1966 7 Sheets-Sheet 6 Nov. 5, 1968 R. 1.. SJOSTROM MEAN FOR FOLDING SHEETS 7 Sheets-Sheet 7 uaua mkii 2% SN w uoziho utzi EN IN N 2 55. 2555 viii: EN

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5 5a m E Filed June 23. 1966 United States Patent 3,409,288 MEANS FOR FOLDING SHEETS Robert L. Sjostrom, Boca Raton, Fla., assignor to Sjostrom Automations, Inc., Boca Raton, Fla., a corporation of Florida Filed June 23, 1966, Ser. No. 559,868 9 Claims. (Cl. 270-69) ABSTRACT OF THE DISCLOSURE A sheet-folding machine for effecting a plurality of transverse folds in a sheet as it moves from the rear to the forward end of the machine. The folding means in clude means for measuring the length of each successive sheet as it moves through the machine. A folding mechanism is actuated when a sensing device has measured a preselected portion of the measured sheet, as measured by the measuring means. The measuring means and sensing means each include a commutator having a plurality of contacts and a rotor rotatable over contacts at preselected, uniform speeds. The measuring means rotor will move from one contact to a second to indicate the length of the sheet measured. The sensing means rotor moves at a different rate when actuated by the leading edge of the sheet and, therefore, will reach a contact electrically corresponding to the second contact reached by the measuring rotor at a different time interval, which permits the sensing device to then actuate the folding mechanism.

The present invention is directed to FIGURES l to 7 of applicants copending application which has now matured into Patent No. 3,294,395.

The present invention relates to an improved means and method of folding sheets of flexible material and, in particular, to an improved means and method of folding sheets up to the size of large bedsheets.

It is customary to place a folding mechanism at the end of an ironer in commercial laundries and linen supply plants. These folding mechanisms which have been used are of substantial size, often up to ten feet in length. Because of their lengths, such sheet folders have limited utility and cannot be used with every sheet ironer.

In addition, such sheet folding mechanisms have involved and complicated electrical and mechanical motions and quite often utilize sophisticated electronic circuitry, which often results in frequent breakdowns and failure of the machines when in constant use.

It is therefore an object of the present invention to provide an improved means and method of folding sheets in which a sheet folder of relatively small size may be conveniently located at the end of any conventional ironer to receive successively fed sheets. A further object of this invention is to provide a sheet folding mechanism which is simple in design, is not susceptible to frequent breakdown, requires little maintenance, and utilizes a very simple folding mechanism having few moving parts, and does not require the use of sophisticated circuitry including vacuum tubes, transistors or comparable components. A further object of this invention is to provide a compact improved sheet folder adapted for multiple lane use and which will bypass small pieces and handle king size sheets as well.

A further object of this invention is to provide a means for effecting successive lateral folds in large sheets in rapid succession with the second fold being formed as the first fold is being completed.

In the present invention there is provided a sheet folding machine for effecting a plurality of lateral folds in sheets that includes means for feeding a sheet in a "ice forward direction to a selective position. Means for effecting at least two successive folds in the sheet transversely of this forward direction are positioned at the end of the feeding means. These folding means include means for automatically measuring the length of the sheet being folded, and means for calculating from this length the precise location on the sheet at which each of the transverse folds are to be effected. This measuring means determines the precise location by synchronizing the operation of the folding means with the movement of the sheet over the folding means.

These and other objects and advantages of the present invention will be more clearly understood when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a cross sectional elevation of the sheet folding machine taken substantially along the line 1--1 of FIG. 3;

FIG. 2 is an end view of the machine shown in FIG. 1 with covering plates shown in broken outline to expose drive mechanisms, with FIG. 2 taken substantially along the line 22 of FIG. 3;

FIG. 3 is a front end view of the machine looking from the right of FIG. 1;

FIG. 4 is a rear end view of the machine looking from the left of FIG. 1;

FIG. 5 is a schematic illustration in enlarged detail of the folding mechanism;

FIG. 6 is a schematic illustration of some of the electrical details of the present invention;

FIG. 7 is a further schematic of the electrical components of the present invention;

FIG. 8 is a schematic cross section of a sheet folder incorporating a preferred embodiment of the invention;

FIG. 9A is a somewhat schematic fragmentary cross section of the sheet folder showing the drive mechanism and taken along the line 9a9a of FIG. 8;

FIG. 9B is a somewhat schematic fragmentary cross section of the sheet folder along the line 9b-9b of FIG. 9A; and

FIG. 10 is a schematic illustration of an electrical circuit used in the embodiment of the invention illustrated in FIG. 8.

In the present invention there is provided a folding mechanism having side frames 1 and 2. These side frames may comprise a double wall member interconnected by webs 3 to form an enclosure adapted to contain various chain drives, sprockets and other components which preferably should be concealed or covered for safety purposes or for improved machine functioning. A plurality of pipe spacers or transverse support means 17 extend between side frames 1 and 2 and hold these frames in rigid inte'rengagement. Suitably journaled between the side frames 1 and 2 is a conveyor system 4 which comprises, preferably, a first conveyor belt means 5, a second conveyor belt means 6, and a third conveyor belt means 7. Conveyor belt means 5 (FIG. 1) is formed of a pair of rolls 8 and 9 parallelly mounted and supporting a series of belts 10 for movement with their upper surfaces 11 in a forward direction.

The first conveyor means 5 has its forward roll 8 suitably journaled at its ends in journals 12 (FIG. 2) in turn secured to the side frames 1 and 2. The rearmost roll 9 is journaled in journals 14 with the journals 14 in turn secured to elongated frame members 16 and 18. The frame members 16 and 18 are in turn pivotally supported on the side frames 2 and 1, respectively, to permit the first conveyor means 5 to pivot about the axis of roll 8. Chains 20 secured at one end to the frame members 16 and 18 are adapted to engage a suitable support on an ironer (not shown) with which the sheet folding means is to be associated. Thus, the upper surface 11 can be positioned immediately below the delivery rolls or belts of an irouer to receive sheets as they move from the ironer.

The second conveyor belt means 6 (FIG. 1) comprises a forward roll 22 and a rearward roll 24 parallelly mounted and journaled in journals 26 and 29 (FIG. 2) in turn secured to the side frames 1 and 2. The rolls 22 and 24 carry a plurality of endless belts 30 with the upper surface 32 of these belts upwardly inclined preferably at an angle of approximately 45. A guide means preferably formed of a plurality of guide figures 34 is positioned rearward of the second conveyor belt means 6, and preferably comprises a cross member 36 supporting a series of parallel arcuate fingers extending arcuately about and in spaced relation to the rearward portion of roll 24, to guide sheets moving rearwardly over the belts 30 toward the third conveyor belt means 7.

The third conveyor belt means 7 comprises a forward roll 38 and a rearward roll 40 parallelly mounted in journals 42 and 44 in turn mounted in the frame members 1 and 2. These rolls 38 and 40 carry a plurality of endless belts 46 having upper surface 48. Roll 40 is positioned preferably below and rearward of roll 24, while roll 38 is positioned forward of and preferably above rolls 8 and 22. The upper surface 48 of conveyor belt means 7 is preferably substantially parallel to the upper surface 32 of conveyor belt means 6 and preferably in partial facing relation with the lower portion of conveyor belts 30. Preferably surface 48 lies at an approximate 45 with the horizontal. A microswitch 50 has its actuating finger projecting upwardly between adjacent belts 46 in the conveyor belt means 7 for purposes hereinafter described.

The folding mechanism best illustrated in FIG. is located at the forward end of the machine adjacent the forward end of the third conveyor belt means 7. In this arrangement there is provided a first fold means 52 and a second fold means 53. The first fold means includes a roll 54 supported on an axis forward of and below the axis of roll 38 with the roll 54 suitably journale-d in journals 56, in turn secured to the side frames 1 and 2. Rolls 38 and 54 have a space 58 formed between them which defines a first line of tangency at which a first fold is effected. A second line of tangency 60 is formed between roll 54 and roll 62, with roll 62 suitably supported by journals 64 with its axis below and preferably slightly rearward of the axis of roll 54. A microswitch 68 is positioned with its finger directed toward the first line of tangency 58 and a micros-witch 70 is positioned with its finger directed toward the second line of tangency 60. An air pipe 72 extends transversely of the machine between the side frames 1 and 2 and is provided with a series of perforations aligned with and adapted to direct a force of air towards the first line of tangency 58. A second air pipe 74 below and rearward of air pipe 72 also extends between side frames 1 and 2, and is provided with a series of perforations aligned with and adapted to direct a force of air toward the second line of tangency 60. Preferably, the air pipe 72 is positioned so that its line of perforation is adapted to direct a force of air downwardly and rearwardly, while air pipe 74 is positioned so that its line of perforations is adapted to direct a force of air forwardly. A cap 76 extends arcuately rearwardly from air pipe 72 over and in spaced relation to roll 38. A second guide plate 78 is parallel to and has its rear edge positioned over the upper forward portion of roll 54. The major surface of this plate 78 is inclined forwardly and downwardly. A third guide plate 80 is parallel to and has its rear end substantially tangential with the forward portion of roll 62. This plate 80 is inclined forwardly and downwardly wtih its lower portion arcuately curved to a position adjacent platform 82. The plates 76, 78 and 80 are all suitably secured at their sides to side frames 1 and 2 with plate 78 below and forward of plate 76, and with plate 80 below plate 78. Plate 80 has its rear edge rearward of the forward edge of plate 78. Plate 78 is adapted to guide sheets passing over roll 54 forwardly and hold them spaced from roll 62. Plate 80 is adapted to guide sheets 4 passing over roll 62 forwardly and downwardly onto platform 82. Platform 82 extends forwardly of the machine and is suitably secured to the side frames 1 and 2 by suitable means which may comprise a pair of rearwardly extending arms 84 at either side in turn secured to the side frames by bolts or braces 86.

The various conveyor belt means and folding rolls are driven from a common drive source by a simple means best illustrated in FIG. 2. Sprockets are mounted on the shafts on which rollers 8, 22, 38, 54 and 62 are mounted. These sprockets 90, 92, 94, 96 and 98, preferably, all lie in a common plane on the side of .a wall member of frame 1 opposite to the side on which the rollers are positioned. A chain 100 operatively interengages each of these sprockets by passing on the outside of sprockets 94 and 98 and on the inside of sprockets 92 and 96. The chain is driven by a motor 102 (FIG. 3) having a shaft 104 which projects through the wall member of frame 1 and has the sprocket 106 mounted on it. A suitable idler sprocket 108 may be mounted on the wall member of frame 1 to take up slack in the chain 100. The chain moves in the direction of the arrow 110, which in turn causes the upper surface 11 of conveyor means 5 and the upper surface 48 of conveyor means 7 to move in a forward direction and the upper surface 32 of conveyor means 6 to move in a rearward direction. The chain also causes roll 54 to move in a counterclockwise direction and rolls 38 and 62 to move in a clock-wise direction, as viewed in FIG. 5. Actuation of the air blast through pipes 72 and 74 are controlled respectively by solenoid valve means schematically illustrated in FIG. 7 at 112 and 114. These solenoid valves have actuating coils 116 and 118 which, when energized, Will open the valves to permit air to pass into the tubes 72 and 74 from a suitable source 120. The circuit in which coils 116 and 118 are connected includes three constant speed motors 121, 122 and 123. For quarter folding bedsheets, motor 122 effectively operates at twice the speed of motor 121 and motor 123 effectively operates .at twice the speed of motor 122. This speed differentiation may be attained by using motors of different speeds or by using suitable gear reductions attached to the drive shaft. Other speed ratios may be used for attaining folds other than quarter folds. These motors are connected between the hot line 124 and ground line 125 by suitable leads 128 for actuating from the alternating current power source 129. A suitable switch 130 may be provided for turning on and off the entire circuit. The armatures 121a, 122a and 123a respectively of these motors 121, 122 and 123, are connected respectively to electromagnetic clutches 134, and 136. These electro magnetic clutches :are used to selectively engage the brushes 138, 139 and 140 of the commutators 141, 142 and 143 respectively with the motors 121, 122 and 123. The brushes 138, 139 and 140 are adapted to cyclically pass over the contacts of the commutators 141, 142 and 143. The commutators 141, 142 and 143 should be substantially identical in construction with equal numbers of contacts in each of the commutators. In the preferred embodiment, 56 contacts are provided. For simplicity, five corresponding contacts, indicated by numerals 1 to 5, in commutators 141, 142 and 143, are shown connected in series by lead 150. For simplicity, only one lead is shown connecting the corresponding contacts in commutators 142 and 143 but it should be understood that each corresponding set of the 56 contacts is connected in series. Power is supplied successively to the contacts of commutator 141 from a DC power supply by the lead 152 which is carried at one end of the rotor 138 to make successive electrical contacts with the contacts of the commutator 141, and is connected at the other end to the power source 129 through a rectifier 153. The lead wire 154 has one end carried by the rotor 139 for making successive electrical connections with the contacts of commutator 142. The other end of this lead 154 is connected to the relay 155. Lead 158 has one end carried by the commutator rotor 140 for successive electrical connections with the contacts of commutator 143 and the other end is connected to relay 159. The clutch 134 is normally open, disengaging the motor 121 and the rotor 138. It is closed to cause rotor 138 to rotate when the coil 160 is energized. This coil 160 is energized on closing of microswitch 50 from its normally open contact 50a to its normally closed contact 50b. This microswitch 50, when closed, carries power between a hot line 170 and a ground line 125.

Clutch 135, when energized, interengages motor 122 and rotor 139 to cause it to move over the contacts at a rate twice the rate of movement of rotor 138. The actuating of clutch 135 occurs on energization of coil 172 which is connected betwen the hot line 170 and the contact arm of microswitch 68. And when the contact arm of microswitch 68 is closed to contact 68a, coil 172 will be energized. Clutch 136 is actuated in a similar fashion to clutch 135. In this arrangement the clutch 136 is actuated by coil 174 to close the normally open clutch and thereby interengage the rotor 140 with the constantly rotating motor 123. The coil 172 is connected between the hot line 170 and the contact blade of microswitch 70, and this coil 174 is energized when the contact blade is closed to terminal 70a of the microswitch 70.

The relay 155 has a coil 155a, which when energized will cause the contact blade 155b of the relay to move from its normal position in contact with contact 1550 to contact 155d. Relay 159 has a similar construction with a relay coil 159a adapted when energized to cause movement of the contact blade from a normal position in engagement with contact 159c to engagement with contact 159d. Contacts 155c and 1590 are both connected to ground line 125. Contact 155d and contact 159d are respectively connected to contacts 180a and 181a respectively of the switch 180 and 181 respectively within the relay assemblies 155 and 159. The contact blades 180b and 181b are respectively connected through lead wires 182 and 184 to the coils 116 and 118 of the solenoid valves 112 and 114 for actuating thereof. The contact blades 180b and 187b are controlled respectively by energization of the relay coils 155a and 159a so that these contact blades close respectively to the contacts 180a and 181a upon energization of the coils 155a and 159a.

The circuit operates in conjunction with the other mechanism as follows: When a sheet passing through the machine engages microswitch 50, the microswitch blade is closed against contact 50b to energize coil 160, thereby interengaging the running motor 121 and rotor 138. The rotor 138 then moves successively over contacts in the commutator 141 and stops after the trailing edge of the sheet has passed microswitch 50 and has thereby allowed the switch to open and the coil 160 to be denergized. For purposes of this example, assume that the rotor 138 reaches and stops at contact 3 in commutator 141, as illustrated in FIG. 7, after the trailing edge of the sheet has passed. The sheet continues to move over the belt means 7. When the leading edge of the sheet is carried by belts 46 of the belt means 7 over roll 38, it then engages microswitch 68. When mircoswitch 68 is engaged its blade closes to contact 68a, thereby energizing coil 172, I

causing rotor 139 to turn when the clutch 135 closes. Since motor 122 is a constant speed motor that rotates at twice the speed of motor 121, the rotor 139 will reach contact 3 in commutator '142 in half the time that rotor 138 reached corresponding contact 3 in commutator 141 from a corresponding starting position. When rotor 139 reaches contact 3 in commutator 142, the sheet which has closed microswitch 68 should be positioned so that its transverse center line is positioned between air tube 72 and the line of trangency 58 (see FIG. 5). At that instant power is passed through lead 152, the series connected contacts .3 of the commutators 141 and 142, lead 154, relay coil 155a, contact blade 155b, contact 155e, and ground line 125. However, upon energization of coil 155a, contact blade 155b is closed from contact 1550 to contact 155d, and at the same time blade 18% closes to contact 180a, thereby energizing coil 116 to open the valve 122 and emit an air blast through tube 7.2. The air blast will remain on until the sheet moves from engagement with microswitch 68. This will occur quite quickly since the air blast blows the sheet at its center line away from this microswitch, as can be seen from the arrangement in FIG. 5.

A similar action occurs after the once-folded sheet drops down and its leading (now folded) edge engages microswitch 70. When microswitch 70 is engaged, coil 174 is energized to close the clutch 136 and cause the rotor 140 to rotate from a position corresponding with the initial position of the other rotors at a speed twice that of rotor 139 and four times the speed of rotor 138. This rotor 140 will thereby reach corresponding contact 3 in commutator 143 in half the time that it took rotor 139 to reach contact 3 in commutator 142. At this point, power through the series arranged aligned contacts of the commutators passes through lead 158 to energize the coil 159a of relay 159. When this occurs, contact blade 15% is moved from contact 15% to contact 159d to energize the coil 118 through the correspondingly moved contact blade 181b and line 184. When coil 118 is energized, the valve 114 is open emitting an air blast through tube 74 as a point half way between the leading and trailing edges of the once-folded sheet. This air blast from tube 74 at a point half way between the leading and trailrolls 62 and 54 at the line of tangency 60, thereby folding it once more into a quarter folded arrangement. The movement of the sheet away from microswitch 70 opens microswitch 70 and causes coil 174 to be deenergized.

The modification shown in FIGS. 8, 9A and 9B is somewhat similar in construction to that shown in FIGS. 1 to 7. Consequently parts not specifically detailed may be formed in the manner similar to corresponding parts in the embodiment of the invention of FIGS. 1 to 7. In this embodiment the folder is suitably formed with side frames and cross braces capable of supporting the various components referred to herein. Suitably supported between the side frames at the feed end of the machine are a pair of approach arms 101 with each approach arm suitably pivotally'secured to a side frame member. These approach arms have a pair of rolls 102 and 103 positioned between them with the ends of the rolls suitably journaled in the opposite approach arms. Also secured to and supported by the approach arms 101 is a pair of links 104 with one link secured to each of the approach arms 101 at a pivoting means 105. The other ends of the links 104 have the approach take up roll 106 suitably journaled between them. An approach tension spring 107 is pivotally secured at one end to the approach arms 101 and at the other to an interconnecting link 108 which in turn is fixed to the link 104. This arrangement exerts a downwardly pivoting tension on the roll 106. The inner end of the approach arm 101 has a lever 110 secured rigidly to it with the free end of this lever 110 connected to one end of an approach balance spring 111 with the other end of the approach lever spring 111 suitably connected to a brace or part of the frame of the folder. Positioned above and beyond the approach arms 101 is an approach drive roll 112. This approach drive roll 112 is journaled between the side frame members of the folding machine with the axis of the roll 112 parallel to rolls 102 and 103. A plurality of belts 113 extend about rolls 102, 103, 106 and 112. Roll 106 is a tension roll taking up slack in belts 13. This assembly comprises a first conveyor system or an approach conveyor system. The approach conveyor belts are positioned at the end of an ironer and adapted to receive ironed sheets or other goods as they are delivered from the ironer. A second conveyor system is positioned with a plurality of parallel endless belts 114 parallel to the lower surface 115 of belts 113. The belts 114 are supported for rotation by the second conveyor drive roll 116 and the second conveyor idler roll 117. Roll 116 is suitably journaled between the side frames at the upper end of the machine while roll 117 is suitably journaled between the sides of lower roll bracket 118. A second conveyor guide plate 119 is positioned between and suitably supported on the sides of frame 118, with this guide plate having an arcuate surface following the contour and spaced slightly from roll 117. A third conveyor system comprises a plurality of parallel belts 120 having an upper surface 121 parallel to the lower surface 122 of belts 114. The belts of the third conveyor system 120 are supported for rotation on the third conveyor drive roll 124 suitably joumaled at the upper end of the machine and the third conveyor idler roll 125 suitably journaled between the sides of the lower roll bracket 118. Positioned forwardly of and below roll 124 is the first transverse fold means 130. This fold means comprises an upper fold roll 131 and a lower fold roll 132. The rolls 131 and 132 are journaled between the side frames in parallel spaced relation to one another with roll 132 slightly forward and below roll 131. Roll 131 is adapted to rotate in a counterclockwise direction and roll 132 in a clockwise direction as viewed in FIG. 8. An arcuate first fold guide plate 134 is suitably supported on a transversely extending brace forwardly of the roll 132. This fold guide plate 134 is formed with an arcuate sector conforming to and parallel with a segment of roll 132 and in a slight rearward direction. Supported between the frames rearwardly slightly above and spaced between rolls 131 and 132 is an air pipe 136 which extends lengthwise of the rolls 131 and 132 and is provided with a series of apertures directed to the space between these rolls. Positioned forwardly of the first fold means is a second fold means 140. This second fold means comprises a pair of parallel rolls 141 and 142 suitably iournaled between the side frames of the machine. Roll 142 is positioned slightly rearwardly of and below roll 141. Positioned rearwardly of the rolls 141 and 142 is the second fold air pipe 143. This pipe 143 is suitably supported on the frame of the machine and is positioned in transverse alignment with the space between rolls 141 and 142 and with a length of the air pipe parallel to the rolls 141 and 142. This pipe is provided with a series of apertures along its length aligned with the space between rolls 141 and 142. Suitable means are provided for supplying air to the pipes 136 and 143 through a controlled valve means. A table guide plate 144 having an arcuate surface is positioned forward of the second fold means 140 with its upper edge 145 spaced forwardly of rolls 142. The space between roll 142 and edge 145 is preferably about /2 to A". This spacing is important for properly handling certain articles such as aprons with long strings. The lower edge of this guide plate 144 is positioned close to the folding table 146 which is suitably secured at its inner end on transversely extending rods 147 which in turn are secured at their opposite ends to opposite side frames of the machine.

The drive mechanism for the rolls described is illustrated in FIGS. 9A and 9B which illustrates the portion of the machine parallel to that of FIG. 8 but on the side of a side frame member opposite to the side on which the rolls of FIG. 8 are illustrated. In this arrangement the following rolls have the sprockets indicated secured coaxially to them: sprocket 112a to roll 112, sprocket 116a to roll 116, sprocket 124a to roll 124, a drive sprocket (not shown) and an idler sprocket 131a to roll 130, sprockets 132a to roll 132, sprocket 142a to roll 142 and sprocket 141a to roll 141. Also supported on the side frame of the machine is a doubler idler sprocket assembly 150 and idler sprocket 151 supported on a take up arm 152, in turn pivotally supported at 153 to the side frame and suitably tensioned by a spring 154 secured at one end to the take up arm 152 and at the other to the side frame of the machine. An adjustable take up sprocket 155 is supported on an adjustable arm 156. Take up sprockets 157 and 158 are supported on an adjustable take up arm 159. Arm 159 in turn is pivotally supported at one end 160 to the frame of the machine and tensioned at the other end by a spring 161 secured at one end to the take up arm 159 and at the other to the frame of the machine. A suitable drive source comprising a motor 162 or the like is connected to the motor pulley 162a which in turn is interconnected with the larger diameter of the double sprocket assembly 163 by an endless V-belt 164. The narrower diameter of the sprocket assembly 163 engages the endless drive chain 166 which also encircles the larger diameter of the sprocket and idler sprocket 155. The narrower diameter of sprocket 150 engages chain 167 which also encircles and operatively engages sprockets 132a, 124a, and 112a. This chain drive 167 further engages but does not encircle idler sprocket 151, sprocket 116a and drive sprocket coaxial with sprocket 131a. A chain drive 168 encircles drive sprocket 131a, idler sprocket 157, idler sprocket 158 and sprocket 141a and operatively engages the inside of sprockets 132a and 142a.

Referring once again to FIG. 8 there is illustrated a bypass system designed to be operated manually for the purpose of deflecting small pieces of sheet material such as napkins, pillow cases and the like which are not to be folded directly to the folding table without traveling through the entire conveyor system of the machine. This feature is important since these machines are ordinarily hooked up to an ironer and consequently all materials which are ironed in the ironer must pass through this folding machine. This bypass mechanism comprises a pair of plates 170 and 171. Plate 170 is arcuate in cross section and extends preferably over an arc of about It is supported along one edge along cross bar 172 which in turn is pivoted at its ends to the side frames. The cross bar 172 is adapted to permit rotation of the bypass plate 171 from the position illustrated in FIG. 8 to a position in spaced parallel relation with the outer portion of roll 124. Plate 171 is a flat plate that extends from one side to the other of the folding machine and is formed with a lip 174 adapted in a bypass position to come in close relation with the surface of roll 124. The lower portion of plate 171 extends down wardly over roll 131 and is pivoted at its lower end to the frame in front of roll 141 at 175. The plates 170 and 171 are pivotally interengaged so that in the bypass position they assume a relative position as illustrated in FIG. 8 and in a nonbypass position they assume a relative position with plate 170 spaced close to roll 124 and plate 171 is spaced away from roll 124. This interoperative means includes links 176 and 177. Link 177 is fixed at one end to plate 171 and at the other is pivotally engaged with link 176. The other end of link 176 is pivotally engaged to the side of the bypass plate 170. A third bypass plate 178 is positioned over roll 116 and is adapted to pivot from the position shown in FIG. 8 when the machine is in a bypass condition to a position in which the rear end 179 of the plate 178 is spaced from the surface of roll 112. The other end of this plate 178 is suitably pivoted to a cross brace supported in turn at its ends to the side frame of the machine. Plate 178 is pivotally interlinked with plate 170 and 171 for common operation by link 180. Link 180 is pivoted at one end to the plate 178 and at the other to the hand lever 181 intermediate the ends of the hand lever. The end of the hand lever opposite its free end is pivotally supported on the frame. A link 1 82 interconnects the lever 181 with the plate 170. This link 182 is connected at one end to the support for bypass plate 170 and at the other to pivot point 183. A guide plate 186 arcuately curved to conform with the surface of roll 122 is pivotally supported on cross brace 187 in turn pivotally secured to the side \frames of the machine. A lever handle 188 is secured to plate 186 to permit pivoting the plate 186 from the bypass position shown in FIG. 8 to an operative folding position in parallel relation to roll 112. Thus a sheet which is to be bypassed through the machine when the machine is in a bypass condition, as illustrated in FIG. 8, will travel over conveyor 113 onto plate 178 and from there upwardly oversurface 121 and out of. the machine over plate 171.

The electrical circuit for activating the folding mechanisms in proper sequence as a sheet is carried over the conveyor belts is illustrated in FIG. 10. Three commutators, 200, 201 and 202 are each separated into equal numbers of parallel conductive segments insulated from each other. In this specific embodiment illustrated, each commutator has 56 segments. The corresponding segments in each commutator are connected in parallel to one another. In the illustration only one segment in each commutator 200, 201 and 202 is illustrated as connected, with these corresponding segments connected in parallel by lead 203. The rotor brush of each commutator is operated by coils 200C,.201C and 202C respectively. The coils are operatively connected to the rotor through an electromagnetic clutch mechanism 'for each commutator, with the clutch mechanism controlled by coils 200D,

201D and 202D respectively.

Also operatively connected to the circuit for selective actuation through rotation of the commutators are valves 205A, 205B, 206A and 206B. These valves control the emission of air respectively through tubes or pipes 136 and 143 (FIG. 8) and are positioned to effect folds at the first and second folding positions. The valves are sole noid actuated by the means illustrated and best understood by a description of the function of the circuit. The commutator brush 200B starts to rotate from a preselected initial position in which all brushes are aligned with corresponding commutator segments. This movement is initiated by the leading edge of the sheet as it moves over belt surface 114 and engages switch 190. This closes clutch 200D through leads 207 and lead 208 which are connected across a power source 209. The commutator brush 200B rotates until the trailing edge of the sheet passes over the switch 190 and thereby opens the clutch 200D. When the leading edge of the sheet engages folding switch 193 commutator brush 201B starts to rotate from the same selected position at which brush 200B started to rotate. This brush, however, is geared to rotate at a speed twice that of the speed of brush 200B. Brush 201B is actuated by the winding 201C operatively connected to brush 201 through the clutch winding 201D. Clutch 201D is actuated in closing the switch 193 through lead 211, normally closed latching relay contacts 212A, lead 213 to the coil 201D and then through lead 214, contact arm 215B of relay 215, lead 220 to power source 209.

When the commutator brush 201B reaches the same corresponding commutator position as brush 200B, the first fold relay 215 is actuated by current flowing from one half the power line through line 233 and commutator brush 200B to brush 201B and the lead 217, coil 215C and the lead 220 which in turn is connected to the other side of the power source 209. Energizing the coil 215C causes the contact arms in the upper half 215A and the lower half 215B of the relay 215 to move. The upper half of the relay 215A opens the circuit through coil 201D controlling movement of the brush 201B there by stopping the rotation of the commutator brush 201B. The lower half of the relay 215B is connected to time delay relays 223 and 224 through the line lead 225. Thus when coil 215C is energized and arms 215A and 215B move downwardly the time delay relays 223 and 224 are also actuated through leads 226 and 225. These time delay relays 223 and 224 are provided to permit precise adjustment of the location of the fold on the sheet folder, and thus may be adjusted for the particular unit being folded. Time delay relay 223 is designed to open the valves 205 which in turn open the air tube 136 to emit an air blast between rolls 131 and 132. Time delay relay 224 is designed to close valves 205. Time delay relay 223 may be adjusted to actuate in five-tenths of a second while the time delay relay 224 may be adjusted to actuate in three-tenths of a second later, thus allowing several tenths of a second for an air blast. The blast is delayed from the time of actuation of switch 193 to allow the moving sheet to move to a desired position over the folding rolls. Power from the relay 215 passes through lead 225 to actuate coils 230, 231 and coil 212B of the latching relay 212 which are connected in series. Actuation of coils 230 and 231 of the relay causes a subsequent actuation of the valves 205A and 205B. Closing contact arm 223A causes power from lead233 passing through lead 232 to actuate the solenoid activated 205A and 205B valves. A few tenths of a second later coil 230 of the relay 223 is opened when the contacts 224A and 224B are moved downwardly disconnecting the lead 225 from the lead 233 to the power source.

When coil 212B is energized contact arms 212C, 212E and 212F which are all connected to the power lead 233 are in turn respectively connected to contacts 212G, 212H and 212I. Power from lead 233 through closed contact 2121 and lead 251 energizes coil 202D thereby causing the armature 202B of commutator 202 to rotate. This armature is geared to rotate at a rate which is twice the speed of the rotation of contact arm 201B. When commutator arm 202B rotates to the same corresponding position that commutator arms 200B and 201B have reached, a circuit is closed through the lead 203 to lead 240. This in turn energizes coil 241C of the second relay 241. The contact arms 241D and 241E of this relay which are normally connected to ground lead 243 in parallel are moved by the energization of the coil 241C. These contact arms are thrown from leads 244 connected to coil 202D operating the commutator arm 202B to a connection with lead 246 which is in turn connected to time delay relays 247 and 248. Lead 246 is connected in parallel to the coils 249 and 250 respectively of the time delay relays 247 and 248. These relays are similar in construction to the relays 223 and 224 and function in operation to cause power to be supplied through lead 251 for a limited period of time to valves 206A and 206B. Relay 248 also has connected to it a reset lead 254 connected to the lower relay coil 212M. Actuation of the relay 248 resets the relay 212 by actuation of the coil 212M.

In the overall operation of this device the leading edge of a sheet being fed over the rollers engages switch which starts the commutator 200 which runs until the trailing edge passes switch 190. The first commutator thus sets a measure of the length of the sheet. Actuation of the second switch 193 causes the second commutator to start moving but at a speed twice the speed of the first. When the corresponding position of the second commutator brush is the same as that of the first, the first air valve is actuated and at the same time the third commutator brush starts to move. When the third commutator brush reaches the same position as the other two, the second valve is closed. The time delays are inserted to allow adjustment of the valve positions. In addition, the latching mechanism 212 is designed to permit second feeding of sheets in a relatively rapid pace so that the first commutator may start to move once again even though there is still a sheet still in process and being actuated On by the second and third commutators.

Having now described my invention, I claim:

1. A means for multiple folding successively fed sheets comprising means for successively feeding sheets over a path from a rear to a forward position,

a pair of fold means positioned along said path for effecting transverse folds in each sheet fed over said path,

measuring means for efiecting a measure of the length of each sheet as it moves over said path,

an actuating means for each of said fold means,

a sensing means for each fold means for successively sensing the presence of sheets as each passes each fold means as it moves over said path,

means actuated by each of said sensing means for measuring a preselected portion of the length of each sheet, means for limiting said preselected portion to a predetermined percentage of said measure of the length of said sheet as determined by said measuring means, means for actuating each actuating means when an end of said preselected portion is aligned with each of said fold means.

2. A means for multiple folding successively fed sheets as set forth in claim 1 wherein said measuring means, actuating means, sensing means and means actuated by each of said sensing means comprise at least in part an electrical circuit having switch means, and wherein said means actuated by each of said sensing means includes motor means actuated by said sensing means to change said switch means positions as each sheet moves in engagement with said sensing means.

3. A means for multiple folding successively fed sheets as set forth in claim 2 including said measuring means and said means actuated by said sensing means each including in part commutator means having a plurality of contacts and a rotor rotatable over said contacts at a preselected uniform speed, means for rotating said rotor in said measuring means as a sheet is being measured, means for rotating said rotor in said means actuated by said sensing means as a sheet is being sensed, and means responsive to a preselected relation between the rotor-contact position of said commutator means of said measuring means and the rotor-contact position of said commutator means of said means actuated by said sensing means, for actuating said actuating means.

4. A means as set forth in claim 3 including a pair of commutator means for said means actuated by each of said sensing means,

to said air blast means with valves therebetween; with said valves operatively controlled :by said *re lay means. i

7. A means as set forth in claim 6 wherein each of said means for rotating said rotor comprises "a constant'speed motor and a clutch means for operatively interengaging said motor and rotor. i

8. A means as set forth in claim 7 wherein each of said motor and clutch means are constructed and arranged to operate at diiferent speeds. v

9. A means as set forth in claim 8 whereinsaid motor and clutch means for said measuring means is constructed and arranged to rotate a motor at twice the speed of one other rotor and four times the speed of the other of said rotors.

References Cited UNITED STATES PATENTS 2,941,797 6/1960 Buss 27069 2,942,874 6/1960 Hajos 270-83 EUGENE R. CAPOZIO, Primary Examiner.

P. V. WILLIAMS, Assistant Examiner. 

